"If we catch you, and we're going to catch you, you're going to be prosecuted," Smith said. "We've got some pretty clever detectives in this department. They'll find out who did these things."
There are also concerns that swatting will lead officers to treat certain 911 calls differently.
"At some point, we don't want law enforcement to feel like this is another cry-wolf situation," Lieu said.
Smith said that's a possibility, but he said officers are being told to treat all 911 calls with caution, even if they know they're traveling to a celebrity's home and the call has the traits of a prank.
The California bill, which is also being proposed by Assemblyman Mike Gatto, would increase the penalties for convicted swatters to up to three years in jail if someone was hurt as a result of their call, and also make them responsible for the costs of the emergency response.
Whitmore and Smith said they did not have precise estimates for how much swatting calls cost, and it does not appear any agency is tracking the phenomenon nationwide.
The term swatting was coined by the Dallas FBI office a few years ago after its agents busted a group responsible for 60 hoax calls around the nation. The group's leader was sentenced to more than five years in prison and ordered to pay more than $75,000 in fines, although most swatting calls are handled by local authorities.
Hoaxers often use a computer and programs available online to trick 911 systems into thinking the distress calls are coming from the address where officers are dispatched, even though the prankster may be miles, or several states, away.
Although the use of Internet phone providers can make it harder to track the callers, "nothing on the internet is ever terribly secret," Smith said. "There's always going to be a trail,"
Spoofing a phone number is legal and used for many legitimate business purposes, but it has become a favorite technique of pranksters to harass strangers or send pizza deliverymen or locksmiths to unwitting targets' homes.
Dr. John Grohol, a research psychologist who studies internet behavior and founded the online community PsychCentral.com, said the motivation for celebrity swatting may be rooted in the hoaxers desire to impact the stars' lives and gain notoriety for themselves in online communities.
"You have to kind of look at it from the perspective that most people don't have a lot of opportunity to affect a celebrity's life directly," Grohol said. "This is a way that a person can feel empowered."
Anthony McCartney can be reached at http://twitter.com/mccartneyAP